The system of the present invention is particularly useful in conjunction with modern lavage devices where the cleaning solution is supplied through the liquid jet cleaning arms. In such devices, it is necessary to replenish the soap or other cleaning solution from time to time as it is consumed in the machine. Typically, this is accomplished by pouring cleaning solution or liquid soap into a reservoir which is permanently built into the lavage machine. Generally, the refilling of such a reservoir is from a large bottle or other container which is used to store the cleaning solution and which most frequently holds a greater amount of cleaning solution than the reservoir in the lavage machine. Thus, it is important for an operator to be careful not to overfill or spill the cleaning solution during the refilling operation.
A variety of applications exist for dispensing liquid soap and the like at a point of use. Such soap dispensers, for example, are widely used in public restrooms to dispense a measured amount of liquid soap onto the hands of the user. Since the soap is stored in a closed container, no unsightly dirty soap bars are left on the counter top. Furthermore, the use of liquid soap within a dispensing container prevents the theft of or removal of soap from the restroom or the like where it is used.
Liquid soap dispensers of the type typically used in public restrooms and which employ a modular or throw-away container for replenishing the soap, are disclosed in the Pat. Nos. to Darr No. 2,965,267; Cassia No. 4,245,627; and Steiner No. 4,391,309. The dispensers which are disclosed in all three of these patents use a replaceable liquid container which is placed upside down in a container holding portion of the dispenser. During placement of a new liquid container, a puncturing or piercing member opens the new container to permit the fluid in it to flow into a sump located immediately below the container. This essentially prevents spilling of liquid soap from the new container during the refilling operation. It is necessary, however, to remove the old container (which similarly was opened or punctured during the original placement in the dispenser) from its inverted position in the dispenser. Thus, any residual liquid soap which may still be present in such a container, may be spilled from or dripped from the container during its removal.
None of the devices disclosed in these patents have any provisions for monitoring the liquid soap level. The only way a user realizes that the container is empty is when both the container and the sump are empty, and no further liquid soap can be withdrawn from the dispenser.
Two other patents to Perrin U.S. Pat. No. 4,164,306 and Batlas U.s. pat. No. 4,489,857 disclose liquid hand soap dispensers with sumps in them. The replacement bottles for these devices have tops which are opened before the replacement bottles are inserted upside down into the containers. Consequently, there is considerable opportunity for spillage of the liquid soap during the refilling operation. Neither of these patents disclose any liquid level monitoring to determine the amount of liquid soap remaining in either the container or the device.
The DeHarde U.S. Pat. No. 3,465,916 discloses a sump system in which bottles for various liquids are first opened and then inserted upside down over the sumps. Consequently, this patent is similar to the Perrin and Batlas Patents. The device of DeHarde, however, includes electrical liquid level monitoring sensors. These sensors are built into and remain in place in the sump. The DeHarde device is refilled from standard bottles or containers for the various liquids which are to be dispensed from the apparatus. Such containers first are opened and then poured into the sump.
Whenever a permanent reservoir or permanent sump remains in place in the dispenser for either a conventional soap dispenser or a lavage machine, there is a strong possibility that over a period of time a residue of old cleaning solution may build up on the interior wall and bottom of the sump. In addition, where a permanent sump or reservoir is built into a machine or device from which liquid cleaning solutions are dispensed, there is a possibility of contamination which can take place during the filling operation. In addition, if one type of cleaning solution, including a first group of chemicals, is used at one time in the machine or dispenser and subsquently a different type of cleaning solution having different chemicals is poured into the sump, there is a possibility of an undesirable chemical reaction taking place. In addition, it is possible that the mixing of different types of cleaning solutions in a sump may result in unwanted build-up of residue in the sump or an incompatible mixture o cleaning fluids.
Consequently, it is desirable to provide an improved disposable liquid dispensing module for use in equipment having apparatus for withdrawing liquid therefrom, such as lavage machines and the like. Such a module, ideally, should be self-contained and capable of simple and effective replacement with a minimum possibility of spillage of the cleaning solution.